Horn device



Nov. 18, 1941. N LEWI 2,263,342

HORN DEVICE Filed Oct. 51. 1940 INVENTOR NORMAN I-T LEWIS ATTORNEYPatented Nov. 18, 1941 UNITED STATES OFFI CE HORN DEVICE Norman F.Lewis, Wilkinsburg,":'Pa., sassignor to The'Westing'house Air BrakeCompany, Wilmerding, Pa.,.a 'corporationof Pennsylvania ApplicationOctober 31, 1940, Serial 'N0.363,724

8 Claims.

This invention relates to horn. devicesand more particularly to the typeembodying flexible .dia-

sound.

The principal object. of the invention is the provision of-an improved.horn device embodying a novel diaphragm .means or unit which, ascompared to prior devices of this type, is more flexible,

is operative by fluidunder pressure over a greater rangeof pressures,.has longer..life,-and-does not' require rasflne adjustments or asgreatexactness in the-manufactureof the differentparts of the view of aportion of the horndevice shownin Fig.

l; and Fig. 3 is a plan view of one of the; diaphragm elements of theimproved-horn device.

Description As shown in the drawing' the horn devicecomprises a body Iand ahornibell 2 which.may be formed .integralwith said body and whichprojects from one end thereof. A flexible diaphragm unit 3 is disposedin the body I and at one face ofsaiddiaphragm unit the body is providedwith anannular cavity 4. .The'horn bell 2 has a passage 5 open to thecavity 4 through an annular disposed a nut 8'havingscrew-threaded'engagement with the'body for movement relative theretotoward or away from said diaphragm unit. This nut has projecting fromits inner face an annular shoulder I arranged in coaxial relation withshoulder I in the body-and adapted to engage the Z outer face of thediaphragm unit3 .oppos'itethat engaged by the shoulder l. -The diameterof the shoulder I9 .is less than-that of the shoulder I so as toengagethe diaphragm unit in an' annular region spaced radially inwardlyfrom the shoulder l,- whereby upon screwing'thenut 8 into the body I thediaphragm unit may be deflected or flexed in the direction-of the seatribiG. Between the nut 8- and diaphragm un'it13. is a chamher I Iwhich'is.inconstantcommunication with the atmosphere through a breatherport I2. I

In cavity 4 there is "disposed a laminated'valve I4 adapted to cooperatewith the annular seat ribB for controlling communication between said:cavity and .thepassage S'in'the horn bell-2, said valvebeing'securedto' the'diaphra'gm' unit as will be "later described. Thedegree of 'flexingof the diaphragm unit 3" and thepressure" with which-10 the valve I 4 isnorm'ally'urg'edagainst the .seat

rib 6 is adaptedto'beadjusted to ades'ired degree "by rotation "ofthenut 8 in the'horn'body 'I as will beapparent.

The cavity 4 is connected through achoke' or .5 restricted port formedinthe'bo'dy I to a pipe "I6 'which'is securedtto the" body. Through thispipe and Tchoke'fluidiunderpressure is adapted .to

be supplied'to 'the cavity 4. from any suitable source and under thecontrol of any suitable'val ve ,20 means controlled manually or in anyotherdesired'm'anner,forteifecting operation of'the horn device.

The diaphragm unit 3' which embodies the present invention "and provides'for' attainment of 5 the objects hereinbefore. enumerated will'now bedescribed in detail.

The preferred form of diaphragm unit 3 shown -in the "drawing comprisesa'pluralitylof disks such as indicated by reference numerals'20, 2Iand22, which are preferably struckfrom sheet metal and rigidly clampedtogether around their outer edges between the shoulders I and III asabove dec'sribed. The disksand2l are provided centrally. with apertures23 and 24 respectively, which are lpreferably of 'the same diameter,while the --disk .22 whichis disposed adjacent the valve- I4. is.provided centrallywith an aperture 25-of smaller diameter.

A bolt. 26" having. .a head '21. disposed .in- .the chamber I Ihas-ahmain body portion --28 '-which extends through and hassubstantially :a sliding .fit in the-aperture-ZEinediaphragm 22.rThe-bolt head Z'I' and body-portion2 8- are joined by-a .cylindricalportion 29 of intermediate diameter which extends through the apertures23 and 24in the diaphragm idisksx20 and 2|. "Theidiameteri ofthis--cy1indrica1'portion.is preferably less than that of the-ap'ertures23 and" 24 so as not'to con- 50 tact the diaphragms and H.

' The body 'portion '28and' cylindrical portion "290i the bolt 26 are"joined by anannular shoulder 30 which tapers outwardly slightly in "thedirection of the bolthead 21. Thistaperisprovided so that the diaphragm'22 will engage the 'bolt only at or adjacent to'the corner or edge ofthe aperture 25,'th'us' providing a substantial line contact only'between the diaphragm 22 an d' the bolt 26.

Aiollow'er" 3I .is mounted. on the body. portion The valve I4 comprisesa plurality of circular disks 33 which are provided centrally withaligned bores through which the body portion 28 of bolt 26 extends. Oneend of this pile of disks 23 is mounted against the face of follower 3|oppo- I site that engaging the diaphragm 22, while engaging the oppositeface of this pile of disks is a nut 34 having screw-threaded engagementwith the end of the bolt, this nut being tightened up againstthedisks'for securely clamping same against the follower 3| and for therebyclamping the diaphragm 22 between face 32 of said follower and theannular shoulder 30 on the bolt.

. With the, diaphragm. 22 thus rigidly secured 'to the bolt the spacebetween said diaphragm and the innerface 35 of the head 28 on the boltis slightly greater than the combined thicknesses of the diaphragms 20and 2| so that with the 'parts of the diaphragm unit-in their normalpositions, as shown in Fig, 2, there will be slight clearance spacebetween the face 35 and the adjacent face of the diaphragm 20, it beingunderstood that under this condition the several diaphragms are allurged into, contact with each other and against the diaphragm 22 due tothe pressure exerted. by nut 8 against the diaphragm 20.

The diaphragm 22 is solid except for the central aperture 25, and sinceit is clamped around its periphery to the body and around the oppositeends of aperture 25 between the shoulder 3|J on bolt 26 and face 32 onfollower 3| it provides a seal against leakage of fluid under pressurefrom cavity 4 to chamber II. This diaphragm is also relatively thin inorder to provide long life without rupturing under repeated Thediaphragm 2| is preferably made in a single pieceflfrom relatively thicksheet material and is provided with a plurality of slots 36 which arespaced from each other and extend radially through the diaphragm fromthe central aperture 24 to a point terminating short of the annularregion clamped between the shoulders I and In. These slots separate thecentral portion of the diaphragm into a plurality of flexiblespring-like sections 31 which are adapted to flex independently of eachother upon vibration of the central portion of the diaphragm unit. Thesespring-like sections 31 also prevent the development of excessiveinternal forces in the diaphragm upon deflection thereof, such as areobtainedv in solid diaphragms, so that said diaphragm will be moreflexible and thereby sensitive to variations in force which control theoperation of the horn-device to produce sound, as will be laterdescribed.

The diaphragm 20 may be like the diaphragm 2| oras shown in the drawing,like the diaphragm. 22.

With'the, parts of the horn device assembled in their working relationshown in the drawing and as above described, the several diaphragmsUnder this condition the diaphragm 20 is out of contact with the bolthead 28 as shown in Fig. 2. The force of the diaphragms 20 and 2|, dueto being flexed, is however applied to the diaphragm 22 which transmitssame in addition ,to its own force to the follower 3| for seating thevalve M, as just mentioned.

Operation I If it is desired to cause the horn device to operate toeffect a signal, fluid under pressure is supplied to pipe l6 by anysuitable means, and from said pipe flows through choke |5 at arestricted rate into cavity 4 at one side of the diaphragm unit 3, theopposite side of which is always at atmospheric pressure throughbreather port I2. When the pressure of fluid in cavity 4 is thusincreased to a degree suiflcient to overcome the flexing force nowacting on the diaphragm unit, said pressure starts flexing said unit. inthe direction away from the valve seat 6. This flexing initially occursin the diaphragm 22 in the region between the bolt 26 and the outerclamped peripheral edge of the diaphragm and will therefore causedeflection of the central portion of the diaphragms 2| and 20 relativeto said bolt. This deflection is opposed as will be apparent by theinitial stress in the diaphragms 22 and 20 and by the pressure of thespring sections3'l of diaphragm After a certain slight degree of flexingof the central portions of diaphragms 20 and 2|, the diaphragm 26contacts the inner face 35 of the bolt head 2'! so that the pressure offluid in cavity 4 applied through the diaphragm 22 to the diaphragms 2|and 2|! then becomes effective directly on the bolt 26 along with thatapplied to said bolt by diaphragm 22.

When the pressure in cavity 4 and thereby the force applied through theseveral diaphragms to the bolt 26 is then further increased to asuflicient degree, said diaphragm unit is operated to pull the valve 4away from the seat rib 6. A vent communication from cavity 4 past valveI4 to passage 5 in the horn bell is thereby opened which has a flowcapacity so in excess of the capacity of choke |5 to supply fluid underpressure to cavity 4, that a sudden reduction in pressure in cavity 4occurs into the horn passage 5. This reduction in pressure on thediaphragm unit permits the forces in the several diaphragms, due tobeing flexed, to promptly return said diaphragm unit to its normalposition for closing the valve I4. The pressure in cavity 4 then againincreases through choke l5 and causes the diaphragm unit 3 to movethrough another cycle of vibration. This vibration of the diaphragm unitwill continue as long as the supply of fluid under pressure to pipe I6is maintained and will be at such a rate as to create vibrations of theair column in passage 5 within the horn bell which will cause the hornto emit an audible sound suitable for signal purposes.

From the above description it will now be apparent that in the normalposition of the diaphragm unit shown in Fig. 2, the diaphragms 26 and 2|and particularly the diaphragm 2| acts merely like a resilient spring tooppose deflection of the relatively thin diaphragm 22 by fluid pressuresupplied to cavity 4 whereby the diaphragm unit will promptly respond toa certain pressure in said cavity and start moving. After the unit isthus under motion the diaphragm 20 contacts the bolt head 26 whereby thepresthe valve l4.

The valve l4 may become slightlyunseated by "diaphragm 22 before thediaphragm 20 engages the bolt head 21, but the degree 01' this.unseating must not be so great that the resultant loss of fluidpressure from said cavity past said valve will prevent the'pressuretherein from building up through choke to the degree 're- -quired forcausing the'diaphragm unit to operate the bolt 26 to fully .unseatthevalve M. It will thus beapparent that the clearance space providedbetween the :bolt head 21 and diaphragm '20, when in their normalpositions-shown in Fig. :2, must not exceed a certain limit. Within thislimit however this clearance space is not critical aslong assuflicient'is provided to get the several diaphragms under motion beforethe diaphragm 20 .contacts the bolt head 21.

It will be noted that the diaphragm 22 is the -only diaphragm which isrigidly secured to the bolt 26 and upon vibration of the diaphragm unitflexes about its substantial-lines of contact -with shoulder 30 on'bolt26 and face 32 on follower 3|.

diaphragms 22 against being-"ruptured by the high operating pressurewhich may be obtained in cavity 4.

'In the normal position of thediaphragm unit shown in Fig. 2, andthroughout a portion of the travel of the central portion thereof, thediaphragms 20 and 2| are substantially free of the bolt 26. 'The slots'36 in the relatively thick diaphragm 3| prevent the development ofdisruptive internal forces therein upon deflection of thediaphragm,while the independent sections 310i the diaphragm act in'the capacity ofsprings to control vibration of the unit as well as to sup- "port thethinner diaphragm 22 against rupture as 'hereinbefore mentioned.

While it is di'fiicultto observe the action of the parts while inoperation, the above description of operation'of the different parts ofthe improved diaphragm unit is believed to be correct. Re-

gardless of this however it has been found that "a diaphragm unitconstructed as shown in the drawing and as abovedescribedaccomplishesall of the objects hereinbefore enumerated, and that horn devicesequipped therewith have been surprisingly successful in service. Morespecifically, this improved diaphragm unit provides the requiredstrengthtoprevent rupture thereof by the high pressures which may besupplied to cavity 4, and it has been found that, due it is believed tothegreaterflexibility of the unit, its useful lifeis indefinite and itwill operate as desired over a wide range ofoperating pressures,

such as from seventy toone hundred and forty pounds per square inch. Ithas also been'found that great accuracy in the manufacture of thevarious parts of the horn device is not required .and. neither is-itnecessary that the nut 8 be adjustediwith any great degree of accuracy.

The benefits to be-derived'fro'm this improved diaphragm unit may berealized in horn devices 5 already in use merely by'the'substitution' ofthe improved unit for the unit previously employed :and thissubstitution orreplacement of units may be eflected' without returningthe device to the factory since any semi-skilled workman with a 10-minimum of instruction willbe capableof effecting same.

While only one illustrative embodiment of the invention has been'shownand described in detail, it is not the intention to limit the scope tothat embodiment or otherwise than by the-terms of the appended claims.

Having now described my invention, what I claim-as new and desire tosecure by Letters Patent, is:

-1.i.A horn device comprising a body, a flexible :diaphragm unit in saidbody adapted to vibrate in response to variations in fluid pressure forproducing sound, said unit comprising a flexible diaphragm clampedaround its peripheral edge -and adapted to prevent leakage of fluidunder pressure from one side to the opposite side thereof and otherflexible diaphragm means also clamped around its peripheral edge andhaving a plurality of spring like sections projecting from the clampedportion thereof and bearing against the first named diaphragm forcontrolling vibra- "tion of said unit and for supporting the first nameddiaphragm against rupture by the pres- "sure of said fluid, andconnecting means associated with said unit operative to provide a rigidconnection between the central portions of said diaphragm and diaphragmmeans after a certain deflection of the'unit by" fluid pressure, thesaid diaphragm means being free of said go connecting means'prior'tosaid certain deflection.

2. A horn device comprising a body, a vibratory laminated diaphragm unitdisposed in said body and clamped thereto around its peripheral edge,and a valve in said body, said diaphragm unit comprising one diaphragmhaving an operating connection with said valve for vibrating said valvewith said'unit and another diaphragm which is normally independent ofsaidvalve, said diaphragm 'unit being normally deflected under stress inone direction for operating said valve to provide a differential offluid pressures on opposite sides of saidunit and being deflectable inthe opposite direction by said differential of 'fluid'pressureforoperating' said valve to destroy said differential, the second nameddiaphragm opposing movement of the unit in said opposite direction,and'means arranged to connect said second"nameddiaphragm with said valveafter a certain initial movement of thediaphragm unit in said oppositedirection.

7 35A horn device comprising a body, a valve in said body,.a vibratorylaminated diaphragm unit idispose'd in said body and clamped theretoaround its peripheral edge, said diaphragm 'unit being normallydeflected under stress in one direction for operating said'valve toprovide a difierential of fluid pressures on opposite faces of said uniti andbeing deflectable in the'opposite direction -by' said differentialof fluid pressures for operating said valve to destroy'saiddifierential, said diaphragm unit comprising two flexiblediaphragmaiza'bolt ccnnecting'said valve to one of said .-idiaphra'gmsfor vibratingi'said valve with issaid one'idiaphragm, said bolt'lhavinga shoulder arranged for engagement by the second named diaphragm after acertain initial deflection of said first named diaphragm in saidopposite direction, said shoulder being disengaged from said secondnamed diaphragm when said valve is in the position provided forobtaining said differential of fluid pressures.

4. A horn device comprising a body, a vibratory laminated diaphragm unitdisposed in said body and clamped thereto around its peripheral edge, avalve in said body connected to said unit and adapted to vibratetherewith to alternately provide a differential of fluid pressures onopposite sides of said unit and to then destroy said differential forthereby causing vibration of said unit'and valve, the connection betweensaid unit and valve comprising a member securing said valve to onediaphragm of said unit for movement therewith, said unit comprisinganother diaphragm cooperative with the first named diaphragm to opposemovement of said unit by said differential of fluid pressures, thesecond named diaphragm being free of said member when said difierentialof fluid pressures is destroyed, and means arranged to connect saidsecond named diaphragm and member after a certain initial movement ofsaid unit under the influence of said differential of fluid pressures.

5. A horn device comprising a body, a vibratory laminated diaphragm unitdisposed in said body and clamped thereto around its peripheral edge, avalve in said body connected to said unit and adapted to vibratetherewith to alternately provide a differential of fluid pressures onopposite sides of said unit and to then destroy said differential forthereby causing vibration of said unit and valve, the connection betweensaid unit and valve comprising a bolt secured to said valve andextending through central aligned openings in the diaphragms of saidunit, means rigidly clamping said bolt to one of said diaphragms at theopposite ends of the opening therethrough, another of said diaphragmsbeing free of said bolt when said diiferential of fluid pressures isdestroyed, and means associated with said bolt adapted to be engaged bysaid other diaphragm after a certain initial movement of said unit underthe influence of said difierential of fluid pressures.

6. A horn device comprising a body, a vibratory laminated diaphragm unitdisposed in said body and clamped thereto around its peripheral edge, avalve in said body connected to said unit and adapted to vibratetherewith to alternately provide a differential of fluid pressures onopposite sides of said unit and to then destroy said differential forthereby causing vibration of said unit and valve, the connection betweensaid unit and valve comprising a bolt secured to said valve andextending through central aligned openings in the diaphragms of saidunit, means rigidly clamping said bolt to one of said diaphragms at theopposite ends of the opening therethrough, another of said diaphragmsbeing free of said bolt when said differential of fluid pressures isdestroyed, and means associated with said bolt adapted to be en aged bysaid other diaphragm after a certain initial movement of said unit underthe influence of said diflerential of fluid pressures, the second nameddiaphragm being provided with aplurality of slots spaced from each otherand extending radially from the central opening in the diaphragm to nearthe clamped portion of the diaphragm thereby providing a plurality ofresilient members which are independent of each other and operative tooppose deflection of the first named diaphragm by said differential offluid pressure and to support said first named diaphragm against saiddifferential of fluid pressures upon connection with said bolt aftersaid initial deflection.

7. A horn device comprising a body, alaminated vibratory diaphragm unitdisposed in said body and clamped thereto around its peripheral edge, avalve in said body connected to said unit and adapted to vibratetherewith to alternately provide a differential of fluid pressures onopposite sides of said unit and to then destroy said differential offluid pressures for thereby causing vibration of said unit and valve,said diaphragm unit comprising two relatively thin outside diaphragmsand a central diaphragm of greater thickness, all of said diaphragmshaving axially aligned openings, the central diaphragm being providedwith a plurality of slots spaced from each other and extending radiallyfrom the central opening therein to near the clamped portion of thediaphragm, a bolt extending through the aligned openings in the severaldiaphragms and rigidly connected to said valve, means cooperative withsaid bolt rigidly clamping one of the outer diaphragms to said bolt atthe opposite sides of the axial opening therethrough, the two otherdiaphragms being free of said bolt when the differential of fluidpressures on said unit is destroyed by said valve, and means on saidbolt arranged to be engaged by the other outer diaphragm after a certaininitial movement of said unit under the influence of said differentialof fluid pressures.

8. A horn device comprising a body, a laminated vibratory diaphragm unitdisposed in said body and clamped thereto around its peripheral edge, avalve in said body connected to said unit and adapted to vibratetherewith to alternately provide a differential of fluid pressures onopposite sides of said unit and to then destroy said differential offluid pressures for thereby causing vi bration of said unit and valve,said diaphragm unit comprising at least three flexible diaphragmsprovided with axially aligned openings, a bolt extending through saidopenings and having a shoulder adapted to engage the inner face of oneof the outer diaphragms and having a head spaced from said shoulder andadapted to engage the outer face of the other outer diaphragm, thedistance between said shoulder and head exceeding the combinedthicknesses of the diaphragms arranged therebetween, a member carried bysaid bolt arranged to engage the outer face of the diaphragm engaged onits inner face by said shoulder, means rigidly securing said memberagainst the said one outer diaphragm and connecting said valve formovement therewith, said shoulder and the surface on said memberengaging the opposite faces of said one outer diaphragm being tapered inan outwardly direction away from the diaphragm to thereby providecontact with the diaphragm only adjacent the opposite edges of thecentral opening therethrough, the said distance between said shoulderand head providing for engagement between said head and said other outerdiaphragm after a certain initial deflection of said unit under theinfluence of said diflerential of fluid pressures for supporting saidfirst named outer diaphragm, the said distance also rendering the saidother outer diaphragm and the central diaphragm independent of said boltat other times.

NORMAN F. LEWIS.

